by killing him. He is not actually killed he has 2 hearts and when one of them stops the other one kicks in and regenerates (changes) him.
the doctor changes every 1 or 2 seasons depends on how good he was in that season
In fact, laws can be establish because of values. People creat laws depending on the values of their society, so values change laws.
Because he helped kids from dyeing and that's what doctors do
I believe the Legislative branch can